Blood Sugar Ninja

Privacy Policy

Effective October 7, 2026

Data stored on your device

The app stores completed guesses, the corresponding glucose reading and trend, symptom tags, dates, target ranges, belt progress, and settings in a local database. Insights and the guess journal are calculated on your device. Demo history is kept separate from personal history. The app does not upload this database to our servers or provide its own cloud sync. Device backups may include app data according to your Apple backup settings.

Connecting Dexcom

If you connect, your username and password are kept in the iOS Keychain. Your username is also stored locally with connection settings. Credentials and connection requests go directly to Dexcom Share over HTTPS; they are not sent to us or PostHog. Dexcom processes these requests under its own privacy policy. The app receives your readings from Dexcom and stores the readings associated with saved guesses locally.

The app uses an unofficial Dexcom Share integration, not the published Dexcom OAuth developer API. It is not affiliated with or endorsed by Dexcom. This connection may change or become unavailable.

Optional usage analytics

If you enable “Share usage analytics” in onboarding or Settings, selected usage and reliability events go to PostHog in its US region. Events include app launches, screens visited, rounds started and completed, connection attempts and outcomes, operation durations, safe error categories, and names of settings changed. Setting values are excluded.

Events include a random installation identifier, session identifier, timestamp, app version, and build number. The persistent installation identifier connects activity from the same installation; these events are not described as anonymous. We use them to understand usage and improve reliability. We do not send your name, Dexcom identity, glucose readings, target values, guesses, symptom tags, health outcomes, passwords, or raw server responses.

Session replay, automatic event and screen capture, and automatic crash reporting are disabled. IP-based location enrichment is disabled and IP event properties are removed; PostHog necessarily receives the network connection. We do not use analytics for advertising, cross-app tracking, or selling data.

Your choices, retention, and deletion

Analytics are optional. Turning them off in Settings stops new analytics collection; it does not automatically delete events already received. Previously sent events remain in PostHog subject to the project's retention settings until deleted. For questions or a deletion request, contact us below. We may be unable to associate an installation's events with your email because we do not collect your name or email in the app.

Saved guesses remain on the device until the app's data is deleted. Deleting the app removes its local database; offloading the app does not. Manage any device backups through Apple's settings. Disconnect Dexcom in Settings to delete the saved Keychain credentials; deleting an iOS app alone may leave Keychain entries. Disconnecting does not erase saved guess history.

Reminders and safety settings

Practice reminders are local notifications, optional, and scheduled only with your permission. They do not send glucose data to a push service. They cannot check your glucose when delivered and are not low-glucose alarms. An observed very-low reading pauses reminders until a fresh non-very-low reading is received. The very-low pause preference and the date you acknowledge disabling it are stored locally, not in analytics.

Intended audience

Blood Sugar Ninja is intended for teens and adults. Analytics are optional and are not required to play. Contact us with privacy concerns about a minor's use.

This policy website

This page uses no analytics, cookies, third-party fonts, or tracking scripts. GitHub Pages hosts it and may process technical request information, such as IP addresses, under GitHub's privacy statement.

Changes and contact

We will update this policy and its effective date when our data practices change. Questions or deletion requests: support@bloodsugarninjaapp.com.